(1) Field of the Invention
The present invention relates to preventing unauthorized access to areas and particularly to the locking of doors. More specifically, this invention is directed to a dead bolt lock. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
(2) Description of the Prior Art
There is, in the art, a demand for dead bolt type locks which may be installed in doors or the like and operated from one or both sides of the door by means of a key. Prior dead bolt locks are characterized by rim cylinders with exposed or weakly shielded attaching screws. The use of such attaching screws significantly reduces the security of the lock. The rim cylinders employed in prior dead bolt locks also have the deficiency of employing "lazy cam" tailpieces which are unique to their respective lock and which are often flimsy in their construction. Further, rim cylinders employed in prior dead bolt locks, because of the use of "lazy cam" mechanisms, are relatively long and thus require extended cylinder collars that protrude from the door and are subject to vandalism.